Solid-Phase Synthesis of Nickel-Molybdenum Catalysts for Propylene Metathesis under Mechanical Activation

Solid-phase synthesis of aluminum-molybdenum (Al-Mo) and aluminum-nickel-molybdenum (Al-Ni-Mo) model composites as part of propylene metathesis catalysts has been conducted under mechanical activation. The structure of Al-Mo and Al-Ni-Mo model composites has been studied by X-ray diffraction analysis, high-resolution transmission electron microscopy, infrared spectroscopy, and diffuse reflectance electron spectroscopy (DRES). The DRES method has shown the presence of isolated monomeric and oligomeric molybdate compounds in the Al-Ni-Mo model composites. Granular metathesis catalysts have been synthesized by molding the Al-Mo and Al-Ni-Mo model composites with aluminum hydroxide and subsequent calcining. It has been shown that the highest activity in the propylene metathesis reaction is exhibited by an aluminum-molybdenum catalyst containing 2.6 wt % Ni, 13.0 wt % Mo, and 32.7 wt % Al. At a process temperature of 200 degrees C, a pressure of 0.1 MPa, and a propylene feed space velocity of 1 h(-1), in the presence of this catalyst, the propylene conversion achieves 33.7%; this fact makes this catalyst promising for practical applications. At the same time, the weight fraction of ethylene and butenes in the reaction product composition is 17.5 and 71.3%, respectively.